This is the last unit in the lesson of Nucleic Acids. By previously explaining the role of gel electrophoresis in separating pieces of DNA, the goal of this lesson is to understand a specific real world utilization of the information in DNA. After discussing detective movies that use DNA evidence to solve a mystery, the students will watch a quick video and and be able to explain the function of restriction enzymes (cut up specific sequences of DNA). In a lab activity, the students will also incorporate cut DNA sequences into a gel electrophoresis, and subsequently create a product (migratory patterns of the various DNA sequences from known and unknown DNA samples). Based on the data they created, the students will determine the identity of the unknown DNA and explain how they came to their conclusion based on the analysis of their data.
RI LS1-2: Students demonstrate an understanding of the molecular basis of heredity by describing DNA structure and relating the DNA sequence to the genetic code. National Science Education Standard
(Content Standard A; 9-12): All students should develop abilities necessary to do scientific inquiry and understandings about scientific inquiry.
(Content Standard C; 9-12): All students should develop an understanding of molecular basis of heredity. Rhode Island Beginning Teacher Standards 2
Teachers create Learning Experiences that reflect an understanding of central concepts and tools of inquiry of the disciplines they teach. Teachers use a variety of explanations and multiple representations of concepts, including analogies, metaphors, and demonstrations and illustrations that help students develop conceptual understanding
Webb level 4 - Extended Thinking (application to real world: create and analyze)
Prerequisite Knowledge
Watching a detective movie
Understanding that the role of DNA base sequences as a defining characteristic of DNA
Understanding the role of gel electrophoresis in separating pieces of DNA
Plans for Differentiating Instruction
I will have a peer teacher help me provide support to those students who are having a difficult time understanding the function of restriction enzymes and gel electrophoresis, as well as conducting the lab experiment
Through the lecture and the lab experiment, I was able to incorporate the tactile, visual, and auditory modalities of learning.
Accommodations and modifications
There are three students who have illegible handwriting. I will allow these students to use a laptop to write the answers to questions as well as their data from their lab experiment
There are three students who have trouble focusing. I will pair these students with a student who is very organized. The organized student will be a good model for the student.
Environmental factors
The students will working in pairs at their table.
There will be two pairs at each table, with six tables total.
Materials
I will need a online video (see engagement part 1)
In the DNA fingerprinting lab,
I will need three different samples of trout DNA.
I will need agar gel electrophoresis
I will need a solution of restriction enzyme
I will need a centrifuging machine
Objectives:
At the end of this lesson, students will be able to
Describe an example of how the information in DNA is used in a real world situation (artefact - understanding how an unknown sample of DNA is compared to a known sample of DNA using restriction enzymes and gel electrophoresis by watching a video, answering questions in their notebook, and conducting a lab activity)
Explain the relationship of the unknown trout DNA to known trout DNA using gel electrophoresis (artefact - After conducting their experiment, the students will write, in their notebooks, about the observed relationship between the migration patterns of the cut sequences from each DNA sample and the number of base pairs in the sequence)
Instruction:
Opening:
1) As I take attendance, the white board will say, name a couple of detective movies where the investigator finds unknown DNA at the scene.
2) I will ask the students the following question: Using your prior knowledge, what do they do with this evidence? (answer - They compare the DNA from the scene to the DNA of a suspect).
3) Today, you are going to conduct an experiment and subsequently explain how technology (restriction enzymes and gel electrophoresis) is used to compare an unknown sample of trout DNA with a known sample of trout DNA.
Engagement
Part 1
1) I will present the following questions on the smart board, using powerpoint.
File Not Found
2) I will ask the students to answer these questions as they view the following quick video (video)
3) The questions include the following:
What do restriction enzymes do? (answer - A specific restriction enzyme cuts DNA at a specific base sequence, based on the specific restriction enzyme used.)
How are these cut pieces of unknown DNA compared to known DNA? (Answer- The migration patterns of these sequences are analyzed in agar gel electrophoresis and are compared to those characteristics of a known DNA sample).
4) The students will write the answer to this question in their notebook. I told the students that they will need this information in order to solve a crime in the next activity. As they watch the video, I will walk around and evaluate their responses in their notebook. There is a picture online that also describes the video (pic is at bottom of website)
5) Today you are going to solve a crime using your knowledge of base pairings of DNA (lesson 1), gel electrophoresis (previous lesson), and restriction enzyme.
Part 2
1) Two poachers in California were arrested because it was thought that they poached their trout off an illegal fishing area off the coast of San Francisco. The police questioned the poachers. The poachers are apparently not good with direction. Both poachers said they did not get their fish from the illegal area, but one poacher told the police that they got their trout from a fishing area off the coast of San Diego, California, and the other poacher said they got their trout off the coast of Mendocino, California. Where did the poacher's fish come from?
2) I will instruct the students to work in pairs.
3) I have DNA samples of trout from each of the three areas.
4) I will give each group a labeled DNA sample from each of the three areas. These will serve as the control.
5) I will then give each pair an unknown sample of DNA. The unknown could be any one of the three different samples of trout DNA. The unknown will serve as the poacher's trout.
6) The students will use a specific restriction enzyme that cuts specific sequences of DNA.
7) These sequences will then be placed into an agar gel and undergo electrophoresis. (The agar gel will be created by the teacher prior to the lesson.)
8) I will walk around and ask the students if they have any question regarding the lab activity. If a student is having trouble understanding a concept, I will ask appropriate questions that will get the student on track.
9) The students will observe and compare the migration patterns of the known and unknown trout DNA. Based on the number of cut sequences from each sample and the number of base pairs in each sequence, the students will compare the unknown to the known samples and determine origin of their unknown.
10) I will ask the students to explain, in writing, their proposed origin of their unknown sample. I will ask the students to explain how they came to their conclusion based on analyzing their electrophoresis data. If the students were not able to match the migration patterns of their unknown DNA to the known DNA sample, I will want the students to explain sources of error.
I1) Since I know which unknown sample I gave each pair, I will know if the pair conducted their experiment correctly. I will evaluate the students by reading their findings (step 9 above) to see if they were able to explain the relationship of their unknown trout to the known trout sample based on the lab activity.
Closure:
I will ask the students: Describe a real world use of the information within DNA?
I will ask the students Explain the relationship between the DNA sequences from the known and unknown DNA samples using gel electrophoresis.
For homework, I would like the students to hypothesize four possible sources of error that could affect the results of their experiment.
I will collect this homework at the beginning of the next period.
Assessment:
Formative questions in the opening
Formative question during the engagement (in notebook)
Analysis of lab data and sources of error within lab experiment (rubric to be added in the near future)
Lesson Title: Let me see your DNA.
Context of Lesson:
This is the last unit in the lesson of Nucleic Acids. By previously explaining the role of gel electrophoresis in separating pieces of DNA, the goal of this lesson is to understand a specific real world utilization of the information in DNA. After discussing detective movies that use DNA evidence to solve a mystery, the students will watch a quick video and and be able to explain the function of restriction enzymes (cut up specific sequences of DNA). In a lab activity, the students will also incorporate cut DNA sequences into a gel electrophoresis, and subsequently create a product (migratory patterns of the various DNA sequences from known and unknown DNA samples). Based on the data they created, the students will determine the identity of the unknown DNA and explain how they came to their conclusion based on the analysis of their data.Standard
RI LS1-2: Students demonstrate an understanding of the molecular basis of heredity by describing DNA structure and relating the DNA sequence to the genetic code.National Science Education Standard
(Content Standard A; 9-12): All students should develop abilities necessary to do scientific inquiry and understandings about scientific inquiry.
(Content Standard C; 9-12): All students should develop an understanding of molecular basis of heredity.
Rhode Island Beginning Teacher Standards 2
Teachers create Learning Experiences that reflect an understanding of central concepts and tools of inquiry of the disciplines they teach. Teachers use a variety of explanations and multiple representations of concepts, including analogies, metaphors, and demonstrations and illustrations that help students develop conceptual understanding
Opportunities to Learn:
Depth of Knowledge
Prerequisite Knowledge
Plans for Differentiating Instruction
Accommodations and modifications
Environmental factors
Materials
- I will need a online video (see engagement part 1)
In the DNA fingerprinting lab,Objectives:
At the end of this lesson, students will be able toInstruction:
Opening:
1) As I take attendance, the white board will say, name a couple of detective movies where the investigator finds unknown DNA at the scene.2) I will ask the students the following question: Using your prior knowledge, what do they do with this evidence? (answer - They compare the DNA from the scene to the DNA of a suspect).
3) Today, you are going to conduct an experiment and subsequently explain how technology (restriction enzymes and gel electrophoresis) is used to compare an unknown sample of trout DNA with a known sample of trout DNA.
Engagement
Part 11) I will present the following questions on the smart board, using powerpoint.
2) I will ask the students to answer these questions as they view the following quick video (video)
3) The questions include the following:
- What do restriction enzymes do? (answer - A specific restriction enzyme cuts DNA at a specific base sequence, based on the specific restriction enzyme used.)
- How are these cut pieces of unknown DNA compared to known DNA? (Answer- The migration patterns of these sequences are analyzed in agar gel electrophoresis and are compared to those characteristics of a known DNA sample).
4) The students will write the answer to this question in their notebook. I told the students that they will need this information in order to solve a crime in the next activity. As they watch the video, I will walk around and evaluate their responses in their notebook. There is a picture online that also describes the video (pic is at bottom of website)5) Today you are going to solve a crime using your knowledge of base pairings of DNA (lesson 1), gel electrophoresis (previous lesson), and restriction enzyme.
Part 2
1) Two poachers in California were arrested because it was thought that they poached their trout off an illegal fishing area off the coast of San Francisco. The police questioned the poachers. The poachers are apparently not good with direction. Both poachers said they did not get their fish from the illegal area, but one poacher told the police that they got their trout from a fishing area off the coast of San Diego, California, and the other poacher said they got their trout off the coast of Mendocino, California. Where did the poacher's fish come from?
2) I will instruct the students to work in pairs.
3) I have DNA samples of trout from each of the three areas.
4) I will give each group a labeled DNA sample from each of the three areas. These will serve as the control.
5) I will then give each pair an unknown sample of DNA. The unknown could be any one of the three different samples of trout DNA. The unknown will serve as the poacher's trout.
6) The students will use a specific restriction enzyme that cuts specific sequences of DNA.
7) These sequences will then be placed into an agar gel and undergo electrophoresis. (The agar gel will be created by the teacher prior to the lesson.)
8) I will walk around and ask the students if they have any question regarding the lab activity. If a student is having trouble understanding a concept, I will ask appropriate questions that will get the student on track.
9) The students will observe and compare the migration patterns of the known and unknown trout DNA. Based on the number of cut sequences from each sample and the number of base pairs in each sequence, the students will compare the unknown to the known samples and determine origin of their unknown.
10) I will ask the students to explain, in writing, their proposed origin of their unknown sample. I will ask the students to explain how they came to their conclusion based on analyzing their electrophoresis data. If the students were not able to match the migration patterns of their unknown DNA to the known DNA sample, I will want the students to explain sources of error.
I1) Since I know which unknown sample I gave each pair, I will know if the pair conducted their experiment correctly. I will evaluate the students by reading their findings (step 9 above) to see if they were able to explain the relationship of their unknown trout to the known trout sample based on the lab activity.
Closure:
Assessment: